Top Wing Centre Section

The good news is the wing kit leaves the US on the 8th of August. Until it arrives however, there is a number of things that I am trying to get finished off so I can focus on the wings when it gets here.

The horizontal stabiliser and elevator are out for media blasting and finish welding. They needed work as they are just starting to get surface rust just sitting in the garage bare and I want to get some primer on them. Thats what you get with humidity I guess.

I am now riveting the upper wing fuel tank. Should have that finished quite quickly but will wait to have it welded because I need to check the clearances in the wing and particularly underneath the tank to make sure the clearance of the drain/fuel line flanges are acceptable. I will build a drilling template also to locate the holes in the lower surface of the wing.

I am also still completing the second and last butt rib for the upper wing, which is different than a butt rib from the standard wing. This rib is a 1/2″ think rather than the standard 1/4″ and has the compression wood within it.

Finally I have been playing with the cabane struts, having been fortunate to scrounge some streamline tubing from a fellow builder in Canberra. Thanks Lou!!

I have had a go at working with aluminium for the first time. Working out quite well.. Right now I have three ribs mostly completed. Two inner ribs with a relief in the corners and one without the relief which will be on the of the ends for the tank. The relief is not cut in the ends as the corners will get welded.

Last thing to do is final sand the edges and then drill/cut the lightening holes with a flanging to finish. Then it will be onto the tank skin.

I remember reading on some build posts about the need for a large number of clamps. I have found myself drawing the same conclusion. I find every time I walk into a hardware store I pick up a couple of clamps of differing kinds as the use of them changes.

I can confirm, if you are building a wooden plane – they are your best friend. I must also say you get very adept at putting them on even with one hand.

Below is some pictures of the laminating process for the hand hold that sits at the rear of the top wing centre section. Most of this will be covered eventually except the middle which will assist the passenger in the front pit extracting themselves on the way out.

Well, all the pieces exist, just now got to get them all assembled. These pics show the spar attach brackets all fitted, the four ribs located and in place and the trailing and nose ribs. Soooo close. The metal rods between the spars are 4130 tubular compression ribs.

You will notice the front spar has the bushings installed (in gray) with the half inch bolts already placed. The front spar is missing the sway wire attach brackets, but otherwise complete. The rear spar has the bushings inserted with bolts and landing wire attach brackets. I will still need to cut the holes in the ribs to fit them, but otherwise its complete.

Some time in the next month or so I will cut and form the grab rail at the back and fit.

Would have to say the Steen CAD plans for this component are pretty good. There is an error on the way the rebates are cut out on the front spar nail strips – they are shown in reverse, otherwise, perfect.

I have found through this phase of the build you can never have too many clamps. This pic is the clamps used to attach and glue the front spar nail strip (it is only ever glued) used to hold the leading edge on.

Once the front nail strips are on, then its time to get to nose ribs glued into place. I tried to get the centre section of the ribs themselves routed out. Got one done and it took forever….gave up and will put up with the incremental weight. Wont be much though.

With the painting done its is time to get these brackets fitted to the spars

The painting was a bit fiddly – two part Stewart Systems top coat. Took me a while to get the paint the right consistency and for it to sit nicely once sprayed. Anyway, once dried it took a few hours to fit and adjust to the point I could tighten all of the bolts.

This last picture shows the reamer in place for the 3/4 inch hole that will have a bushing inserted through the spar.

I have spray painted over the years, but only rarely. This time however I am faced with priming and then painting a finish coat – that is a two part paint. I am going to use Stewart Systems all the way through, but I must admit the finish coat made me nervous.

Primer first. Stewart EcoPrime is one part primer. Opening it, its like water. Stirs up easily and you just shoot it off. It went on beautifully. Here I am thinking this is going to be easy!!. New cheap paint gun, new air hose – nice primer job. How good is this!!

So primer done, all is looking good. Now for a dry and sand and onto the finish coat.